package com.xinqi.utils;

import cn.hutool.core.lang.UUID;
import org.springframework.core.io.ClassPathResource;
import org.springframework.data.redis.core.StringRedisTemplate;
import org.springframework.data.redis.core.script.DefaultRedisScript;

import java.util.Collections;
import java.util.concurrent.TimeUnit;

/**
 * @author xin麒
 * @date 2023/2/21 22:26
 */
public class SimpleRedisLock implements ILock {

    private String name;
    private StringRedisTemplate stringRedisTemplate;
    private static final String KEY_PREFIX = "lock:";
    private static final String ID_PREFIX = UUID.randomUUID().toString(true) + "-";//step1 设置id的唯一性

    public SimpleRedisLock(String name, StringRedisTemplate stringRedisTemplate) {
        this.name = name;
        this.stringRedisTemplate = stringRedisTemplate;
    }

    @Override
    public boolean tryLock(Long timeoutSec) {
        String threadId =ID_PREFIX +  Thread.currentThread().getId();
        Boolean success = stringRedisTemplate.opsForValue()//同时设置键值对和时间
                .setIfAbsent(KEY_PREFIX + name, threadId + "", timeoutSec, TimeUnit.SECONDS);

        return Boolean.TRUE.equals(success);
    }
    private static final DefaultRedisScript<Long> UNLOCK_SCRIPT;
    static {
        UNLOCK_SCRIPT = new DefaultRedisScript<>();
        UNLOCK_SCRIPT.setLocation(new ClassPathResource("unlock.lua"));
        UNLOCK_SCRIPT.setResultType(Long.class);
    }
    @Override
    public void unLock() {
        // 调用lua脚本
        stringRedisTemplate.execute(
                UNLOCK_SCRIPT,
                Collections.singletonList(KEY_PREFIX + name),
                ID_PREFIX + Thread.currentThread().getId());
    }
/*    @Override
    public void unLock() {
        String threadId =ID_PREFIX +  Thread.currentThread().getId();
        String id = KEY_PREFIX + name;
        if (threadId.equals(id)){//step2 判断是不是再删除
            stringRedisTemplate.delete(KEY_PREFIX + name);
        }
    }*/
}
